Cap and shell fastening for lamp-socket casings.



E. H. FREEMAN.

CAP AND SHELL FASTENING POR LAMP SOCKET GASINGS.

AP1 LIOAT10N FILED MAY 17, 1913.

1,096,422. Patented May 12, 1914.

IA. A A

@nue/nto@ 795% @eM/91V Frio EDG-Ali, FREEMAN, OF TREN TON, NEW JERSEY.

CAP All@ SHELL FASTENING FOR LAMP-SOCKET CllSIIlGS.`

i ,onesta-e.

Specification of Letters Patent.

Patented May 12, 1914i.

Application filed May 17, 1913. Serial No. 768,234.

To all wim/m, t 'may concern:

Be it lniown that l, Encan l-l, FREEMAN, a citizen of the United States, residingI at ',lrenton, in the county of Mercer and State of New Jersey, have invented certain new and usctal improvements in Cap and Shell Fastenings `for Lamp- Socket Casings, ot which the following is a speciiication.

This invention relates to the subject of metallic casingsfor electrical lamp sockets, and more particularly to casings of the adyinstable type wherein a plurality of locking' positions are provided between the shell and mp parts ot the casino; so'as to enable the casing shell to not only be readily and se-` purely united to the cap after the latter has been fitted in place, but also to permit the shell to be so positioned when locked to the capas to present the switch-key (of a key socket) in a readily accessible and convenn 'wat position for manipulation. To this end the present invention contemplates a simple and reliable fastening; connection between the shell and cap parts of the lamp socket casing, which admits of practically a universal circular adjustment for the shell so that the same may be locked by the same locking means in any of a number of diifercnt positions, while at the same time pre serving all ofthe desirable features of that type of lamp socket casings having what is termed in the trade a snap fastening.

A inrther object ot the invention is to provide an improved instelling` connection between the shell and the cap parts of a casing; which dispenses with the necessity of a locking hole orits equivalent to secure the locked parts against rotationlin either directon. and against separation, thus greatly simplilyinnf a fastening of this character while at the same time retaining the mani mum strength of the casing.

lilith there and other objects in view, the

consists in certain novel combinai l arrangements oli-*parts as will u appear as the description procreda9 thU novel features thereof being; point ed out ia the appended claims.

For a itull understanding of the invention, reference is to be had to the following description and accompanying drawings, in which :W

lip'r o l is a perspective view of a lamp J socket casing constructed 1n accordance qwith the invention, the cap being shown as separa ted from and elevated above the'body portion 'of the casing. Fig. 2 is a vertical sectional view through the complete casing showing` the position assumed by the parts after one end of the shell hasbeen forced into the cap, but before the shell has been rotated to bring the lugs of the cap under the lateral arms of the bayonet slots of the shell. Fig. 3 is a similar view showing the position assumed by the parts after the shell has been rotated to bring the lugs of the cap beneath the lateral arms of the bayonet slots, the view also showing the fastening latch moved to a kicking.;r position at one side of the lug in one of the slots. Figs. 4 and 5 are similar enlarged detail sectional views, on the line of section indicated by the line www in Fig. l, illustrating the mounting of the slidable fastening latch and also respec tively in its idle and lockingr positions.

Like reference characters designate corresponding parts in the several figures of the drawings.

'lhe improved fastening forming the subject matter of this application may be employed in connection with any approved type of two-part casing for electrical lamp sockets, although for illustrative purposes the invention is shown in the drawings as embodied in a metallic lamp socket casing comprising a metallic shell or body part 1 and a cap part 2,the said cap part being provided with a peripheral flange 3 which telescopically receives an end portion of the shell or body portion 1.

The end of the shell l which is telescopically engaged by the flanged portion of the cap Q is formed with a series of equidistant or regularly spaced bayonet positioning slots fl which open through the end of the shell. rlhe end of the shell may also be formed with a suitable slot or openin 5 to receive the switch key, although this slot may be omitted where the key is not used. The hanged portion of .the cap 2 is formed with a series of inside equidistant lugs 6 of the same size', shape, and projection, and which correspond in nun'lber and osition to the bayonet positioning; slots l o the shell l. It will thus be obvious that by inserting the end oil" the shell or body portion 1 into the cap i2 in such a manner that the lugs 6 will enter the bayonet slots 4t, and then rotating the shell or cap to bring the lugs into the lateral arms ofthe bayonet slots an interlocking connection will be produced which will hold the shell and cap .together and prevent the `said members from beingy separated by a direct pull.

According to the present invention, the mouth of one of the bayonet positioning slots 4 is adapted to be covered and uncovered by means of the movable latch' designated by the numeral l7 and adapted to be moved into a locking position within the mouth of one of the slots and at one side of the holding lug or projection therein. vThe movable fastening latch 7 is designed to be suitably supported on one member of the casing, preferably the shell. While the latch may be diderently constructed and mounted in dierent ways without departing from the invention, the same preferably consists ofa single strip of thin sheet metal `which consists of what may be appropriately termed a slide bolt which is suitably vguided for. sliding movement on the shell or sleeve part of the casing. klDi'erent fexpedients may be resorted to i`n order to slidably support the fastening latch on the shell in such a manner that it forms a permanent part of the fixture, but one way of accomplishing this is shown in the drawings andconsists in mounting the latch for sliding movement through a guide opening 8 formed inthe shell and having one end of the latch forming strip'folded'or looped as at 9, vforming a guiding loop that slidably embraces an edge portion ofthe shell, thereby securely holding the latch in place while at the same time permitting it to have its necessary movement.

The fastening latch 7 is formed at one end with a finger iange l() by means of which it may easily be manipulated, and at an intermediate point the latch is formed with a catch projection 1l made by a prick punch or otherwise, which catch projectionv is adapted to have a snap engagement with a corresponding keeper indentation or recess 12 punched or otherwise formed lin the metal of the shell, as may be best seen in Figs 4 andl 5 of the drawings. -When the latch is moved to its locking position within the mouth of one of the bayonet slots, the projection 11 snaps or springs into engagementwith the recess 12, thereby securely retaining thejlatch in its said locking position, while at the same time not interfering with it being slid toits retracted position for the purpose of unlocking the shell.-

TWhen applying the shell to the cap part of the casing, the fastening latch is retracted to its out-of-the-vvay position shown in Fig. l of the drawings, thereby permitting the slotted end ofthe shell to be inserted in the cap, as plainly shown in Fig. 2 of the drawings.. lin this position of parts, each of the holding lugs 6 engages in one of the bayonet positioning slots. Upon partial rotation of the shell (or of the cap as conditions may sometimes require), the lugs 6 are carried into the 4lateral portions of the bayonet slots as shown in Fig. 3 ofthe drawings, whereupon it is simply necessary to slide the latch '7 longitudinally to bring one end thereof into` the mouth of one of the positioning slots and at one side and against 'the shoulder of the particular lug in that slot. In this position of parts, the cap and shellare vpositively locked against displacement in any direction, either longitudinally, or rotatively in either direction, but to release theparts this may be'readily accomplished by retracting the fastening latch, and reversing the operations above described.

' Attention may be directed to the fact that with-the bayonet positioning slots 4 and the lugs 6 arranged at uniform intervals, the casing may be interlocked with the cap with the key receiving slot 5 on any side thereof, the fineness of the adjustment which is possible depending upon the number of bayonet slots and lugs 4which are employed. lt will beobvious that any desired number of the bayonet positioning slots may be utilizedl` although for ordinary purposes it has been found that four of these positioning slots answer all practicali requirements.

What I claim is l. A lamp socket casing including a cap member provided with a lug, a shell provided with` a, bayonet positioning slot to receive the lug, and a fastening latch consisting of a strip slidably supported on the shell and movable into the mouth of the slot at one side of the lug engaged therein.

2; A lamp socket casing including a cap member provided with a lug, a shell membcr provided with a bayonet slot to receive the lug, and a fastening latch consisting of a strip slidably supported for a limited movement on the shell and movable into the mouth of the slot at one side of the'lug engaged therein, and retaining means for holding the latch in its locking position.

3. A lamp socket casing including a cap member having an interior lug, a shell memloer having a bayonet slot to receive the lug and a keeper recess, and a fastening latch slidably mounted on the shell for a limited movementto engage at one side of the lug when engaged in the slot, said latch also being provided with a catch projection having a snap engagement with the said recess.

t. A lamp socket casing including a cap member provided with a lug, a shell member provided with a slot to receive the lug, and a guide opening, and a fastening latch slidably mounted for a limited movement in the guide opening of the shell and having a looped end slidably engaging an edge portion of the shell, said' latch also having a mounted on the shell for limited movement 10 linger piece and movable into the mouth of l and movable into and out of the mouth of said slot at one side of the lug therein. l one of the bayonet slots.

5. A lamp socket casing including a cap In testimony whereof I hereunto affix my member provided with a plurality of similar f signature in the presence of two witnesses.

equidistant lugs, a shell member provided EDGAR H. FREEMAN. with a plurality of similar bayonet slots cor- Witnesses: responding in number and spacing to the i MARY S.. CURTIS,

said lugs, and a fastening latch s1idably| ADA MARSH. 

